OPTIMUM DESIGN OF INTERBASIN TUNNEL SYSTEMS1

Interbasin water transfer is often accomplished by tunnel systems discharging the water from subreservoirs into a main reservoir. Such a system involving an arbitrary number of reservoirs is considered and an iterative method is developed for the determination of all tunnel sizes giving minimum total cost of the system when the individual discharges from the subreservoirs and elevations of the water surfaces of all reservoirs are known. It is assumed that all tunnels are flowing full. Influence of average construction cost per unit volume as well as tunnel roughness and cross-sectional shape is taken into consideration. The corresponding computer program for the general case is presented. The method may also be adapted to pipe systems, open channel systems, or combined systems by introduction of the proper cost functions for these conduits.     

INTERBASIN TRANSFER-THE INTERNATIONAL DIMENSION1

ABSTRACT. A number of interbasin transfers are technically possible on an international scale but extremely few have been developed or are in prospect of early development. The institutional constraints are strong and nationalistic reactions to proposals which strongly favor either one of the nations involved have contributed to delays in development. Many of the more striking illustrations of the problems and opportunities relating to international transfers are present in the proposals for Canadian water export to the United States. Some have antagonized Canadians and made further negotiation difficult but phased and sequential transfers are possible and some could complement Canadian development. An important early phase might be the provision of guarantees for replacement supplies in option agreements that would free current surpluses within the United States for more intensive use. It should no longer be assumed that engineering development will provide adequate benefits for the source region. Allowances for opportunity costs, environmental improvements and some profit on sales appear to be needed for upstream areas if transfers are to be made. Many hazards are present but these can be more than offset by the opportunities if both countries strive for mutual benefit through rational study and continuing negotiation.     

ROAD DE-ICING SALTS IN AN URBAN STREAM AND FLOOD CONTROL RESERVOIR1

ABSTRACT: High concentrations of chloride and sodium were found in the bottom layers of a new flood control reservoir at the beginning of winter thaw periods. The reservoir had a number of significant downstream impacts. After short thaw periods, discharge from the bottom of the reservoir tended to cause higher salt concentrations downstream in comparison with upstream sites. During long thaw periods or when large quantities of rain fell, downstream salt concentrations were considerably less than upstream values. Average chloride and sodium content of soil at the bottom of the reservoir more than doubled as a result of impounding runoff waters for one winter.     

INTERBASIN WATER TRANSFERS IN RIPARIAN STATES: A CASE STUDY OF GEORGIA1

ABSTRACT: Under the riparian doctrine of eastern states, transfers of water to nonriparian lands and, thus, to different river basins, are only possible if the natural flow theory has been modified to allow for reasonable use. Even this adaptation is too nebulous to provide water managers and water users with certainty regarding water transfers. To provide a more precise mechanism for allocating water, 14 eastern states have adopted some form of administrative permitting process. Of these, five states statutorily allow for interbasin transfers of water. Thus far, no states have successfully issued permits for interbasin water transfers but Georgia and South Carolina are positioned to do so. Whether the permitting process will deter court action may rest on the ability of affected parties to negotiate an equitable agreement.     

DESIGN FREEBOARD AND ECONOMIC EFFICIENCY1

Design freeboard is an increment of height added to a dam, floodwall, levee, or channel, above and beyond the design flood height, intended to serve as a safety factor to account for unforeseen errors in design. Current policies of the Corps of Engineers with regard to the handling of design freeboard for local flood protection studies in economic analyses lead to economic inefficiency. An analysis of these policies in the case study of a levee raising plan for Wyoming Valley, Pennsylvania, reveals that a $200 million project which is considered economically justified under anent policies is in fact not justified under strict economic efficiency criteria Congress has directed that water resources development projects be planned for the objective of National Economic Development. Under current policies that is not being done.     

WATER SUPPLY,TREATMENT, DISTRUBTION,AND REUSE OPTIMIZATION IN ARID URBAN AREAS1

ABSTRACT: A Management level model has been formulated in which a system analysis format is employed to answer some of the basic questions regarding urban water management strategies The model incorporates a multilevel optimization scheme to coordinate urban water supply, distribution, and wastewater management. A test of the model's utility is made in an application to the water management problems of the Denver, Colorado metropolitan area. Denver has utilized both agricultural transfers and transmountain diversions to supplement the natural stream resources of the South Platte River. Although plans are being made to increase the capacity of these sources, increasingly stringent standards on the area's effluents are enhancing the feasibility of reclaiming and recycling a portion of the wastewater. The urban model used in this study indicates the decision points at which respective strategies are introduced. However, by formulating the model from a planner's viewpoint, the most important results gained from the analysis are the costs of various institutional constraints which may restrict the decision maker's ability to implement optimal policies.     

A PLANNING METHOD FOR EVALUATING DOWNSTREAM EFFECTS OF DETENTION BASINS1

While storm water detention basins are widely used for controlling increases in peak discharges that result from urbanization, recent research has indicated that under certain circumstances detention storage can actually cause increases in peak discharge rates. Because of the potential for detrimental downstream effects, storm water management policies often require downstream effects to be evaluated. Such evaluation requires the design engineer to collect additional topographic and land use data and make costly hydrologic analyses. Thus, a method, which is easy to apply and which would indicate whether or not a detailed hydrologic analysis of downstream impacts is necessary, should decrease the average cost of storm water management designs. A planning method that does not require either a large data base or a computer is presented. The time co-ordinates of runoff hydrographs are estimated using the time-of-concentration and the SCS runoff curve number; the discharge coordinates are estimated using a simple peak discharge equation. While the planning method does not require a detailed design of the detention basin, it does provide a reasonably accurate procedure for evaluating whether or not the installation of a detention basin will cause adverse downstream flooding.     

水库型饮用水水源地一级保护区隔离防护工程研究

依托于地理信息系统空间数据管理和空间信息分析的功能,利用高分辨率遥感影像研究隔离方案划定的技术流程。该技术流程主要包括收集水源地基础资料、解译高分辨率遥感影像、提取土地覆盖分类信息、建立空间数据库、划定物理隔离和生物隔离的区段。该种技术流程也适用于地形复杂、一级保护区面积较大的地下型水源地。     

THE VALUE OF STREAMFLOW FORECASTING IN RESERVOIR OPERATION1

ABSTRACT: The value of streamflow forecasts in reservoir operation depends on a number of factors and may vary considerably. Assessment of forecast benefits is presented here for three specific systems. Statistical streamflow models of increasing forecasting ability are coupled with a recently developed stochastic control method in extensive simulation experiments. The performance of the system is statisticafly evaluated with regard to energy generation and flood and drought prevention. The results indicate that forecast benefits are system specific and may range from quite substantial to fairly minimal.     

ADAPTATION TO ARIDITY: WATER DEVELOPMENT IN SOUTH AFRICA1

ABSTRACT The Republic of South Africa, legatee of a three-century history of recurring drought, is firmly committed to a program of the optimum use of its water for the national benefit. Its water law encourages centralized planning in that water is held to be the property of the state and is assignable without requiring acquiescence by the basin or province of origin. Interbasin diversions from the Tugela River to the Vaal River Basin, from the Orange River to the Fish and Sundays River Basins, and from several basins to Cape Town are under construction as are facilities for water importation from Lesotho and Angola. For satisfaction of demands beyond the year 2000 the nation may depend increasingly on a shift of its power production and water-using industry from the coal fields of the central plateau to nuclear power development with associated desalination along its coasts. Alternatively, and preferably, it may cooperate in a co-prosperity bloc in Southern Africa aiding the economies of its neighbors by development for mutual advantage of the water and power resources of the Okavango and other northern rivers.     

INTERBASIN TRANSFERS: DO WE NEED THEM?'

ABSTRACT
Three main issues are discussed: the demands for additional water stemming from population dispersion; supply alternatives to large-scale interbasin transfers; and the displacement of agriculture from nonprofit regions. It is concluded that population dispersion is unlikely to increase aggregate water demands; that large additional supplies are available from other sources at lesser costs; and that a very likely consequence of large-scale transfers will be the displacement of agriculture in other parts of the country.     

OPTIMAL OPERATION OF SHELBYVILLE AND CARLYLE LAKES1

ABSTRACT: Dams were built by the U. S. Army Corps of Engineers on the Kaskaskia River at Shelbyville and Carlyle in Illinois, in 1969 and 1967, respectively. The operation of the Shelbyville and Carlyle Lakes has changed over the years because of considerably lower bankfull channel capacities downstream of the dams than were adopted in the project designs. This study was conducted to review the present operation policy. Intent was to derive a policy for maximizing the overall benefits (or minimizing the overall damages) and to compare these benefits or damages with those with the present policy. The operating rules were optimized through a simulation model which was structured considering the physical nature of the system and the desirable operation in the best interest of various beneficial uses. The expected annual value of overall benefits from recreation and agriculture is shown to increase by $0.2 million with the optimal policy. With the optimal operation, the overall damages are reduced by 76 percent on the average over the 24 years of flow record at Shelbyville and Carlyle.     

Sustainable land-use planning: revitalising a flood prone office park

This paper describes an applied research project that used a sustainable land-use planning approach to examine flood hazard mitigation alternatives in a 536-acre developed office park complex. A watershed-wide assessment including floodplain remapping and modelling of low-impact and large stormwater improvements throughout the upper watershed revealed limited impact on reducing flooding downstream in the environs of the office park during large storms. Thus emphasis had to be given to recommending retroactive sustainable land-use development actions such as relocating buildings and roadways out of the 100-year floodplain, which involves creating a mixed-use overlay district on high elevations, and restoring the floodplain.